Hey Tom V, how would you design a "small" sub?

Discussion in 'Archived Threads 2001-2004' started by Pep Guidote, Jan 20, 2002.

  1. Pep Guidote

    Pep Guidote Agent

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    How would you design a "small enclosure" subwoofer worthy of carrying the SVS name? I know you mentioned in this thread that SVS isn't touching the market for small subs due to patent roadblocks, but what if there weren't any? Have you "dabbled" with small?
    There seem to be quite a few HTF'ers that just didn't get that WAF/SAF because of the size issue. Just curious here. Personally, I'm ok with the looks of my 20-39PC, but its just too big to hide for people that don't. [​IMG]
    BTW, if you have a design in the works and don't want to discuss it here, that's cool.
    -Pep
     
  2. Tom Vodhanel

    Tom Vodhanel Cinematographer

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    Designing a cube isn't any different than a larger enclosure. I would match the driver compliment to the PRs/porting(when applicable)to produce the type of sound SVS is know for. The cost/performance ratio suffers because the efficiency drops off a cliff though.
    SVS has the CS+ about to begin shipping, the SS won't be far behind...then we have the PC+,the PC_U,the SS_PC,and 1 or 2 *xx_x* units on the boards...for spring-summer 2002 rollouts hopefully.(and Valentines day is coming up too [​IMG] ) After that, we might have a surprise or two for the mini-cube enthusiasts...
    We'll get our sleep at CES 2010...
    TV
     
  3. Daniel Mai

    Daniel Mai Stunt Coordinator

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    Hi Tom,

    Regarding your PC+ line, I'm very close in ordering a 20-39PC for my small(12'x14') room. I'm I gonna kick myself for not waiting until the PC+ comes out? When do you think that's going happen?
     
  4. Tom Vodhanel

    Tom Vodhanel Cinematographer

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    The PC+ won't be shipping for a minimum of 60 days. More likely 90-180 days. It would certainly make a viable alternative to the 20-39PC(although it's going to be more expensive obviously). I'm not sure if waiting 3-6 months is something you'd consider an option though.

    TV
     
  5. Randy G

    Randy G Second Unit

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    Mini-cube, Mini-cube, Mini-cube YEAH!!!
    Sealed design, sealed design, sealed design YEAH!!!!
     
  6. Michael R Price

    Michael R Price Screenwriter

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    I'd think that making a small subwoofer live up to the performance and value standards SVS has set would be a very hard thing to do.

    You'd need a completely new driver designed to work with small enclosures... you'd probably have to use PRs instead of ports (costing more money), or go to a sealed enclosure which would lose even more deep output... and it would be hard to get down in the 20-25Hz range without using equalization (which would kill your clean output potential and require a larger, more expensive amplifier). Right?

    If SVS made such a sub, it would probably be more like all those other subs out there, and less like SVS. Then they might also run into all those issues with other companies complaining about patent infringement, etc. Of course, I'm not saying it can't be done... but there would be a big tradeoff. I think someone said that there's a tradeoff between smaller box size, bass extension, and output... if you gain on one, you lose some of the others (smaller box means less output and extension, more extension means larger box and less output, etc).
     
  7. Tom Vodhanel

    Tom Vodhanel Cinematographer

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    Michael...I agree.

    Randy,

    Remember...while *sealed* is automatically assumed to provide the best bass by the golden ears...

    1)you trade off efficiency

    so you need to pump more amp into the driver. More amp = more heat...so you'll eventually run into a point of sonic degradation because the VC is so hot.

    2)you'll have the sub rolling off at the enclosures Fs(typically in the 35-70hz range)...you can counter this with EQ like most companies do...but that introduces 3 problems in itself,

    a)EQ eats amp headroom

    b)VC heating

    c)possible problems with phase shifting when there's a ton of EQ needed.

    This isn't to say a small sealed cube can't sound good...but don't assume a small PRed cube would be inherently compromised because it isn't sealed.

    TV
     
  8. Greg P

    Greg P Stunt Coordinator

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    I have been learning a bit about DIY and here's an idea for a mini sub.

    1. How about a 16" sonotube x 16" facing horizontal instead of vertical and then a plastic base securing it.

    2. If you could get a modifyed TV-12 or the new SS driver to have a lower Vas, and having an FS up to 25hz (like the blue print drivers)and not going below 91db effeciency you wouldnt have to have too big of an amp.

    3. You could use a 15" PR on the back of the tube. A 15 SLAPS PR from Earthquake would yield the displacement your looking for!! (Of course that would lead to legal problems)It does seem possible you could do this for a reasonable price, it seems your biggest problem is finding the perfect passive radiator.
     
  9. Randy G

    Randy G Second Unit

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    Tom,
    Thanks for the info. I guess I just have a hard time getting the distortion figures of the Sunfire out of my head; small cube + PR = distortion in the midbass. Actually, I was thinking more along the lines of the Velos. If you could source the right amp(and add just a bit of EQ, lose the servo), you could bring out a similar product at a considerable savings. No, the performance wouldn't be equivalent to the "waterheaters", but then again, I doubt that most folks would expect it to be. I'd think that the performance of the Velo HGSs would be a decent target, although I recognize that the legal issues could be problematic. Back to that mini-cylinder idea.....
     
  10. Steve WC

    Steve WC Stunt Coordinator

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    With all the new models being released by SVS, maybe the price of the older models will go down (wink, wink).
     
  11. Tom Vodhanel

    Tom Vodhanel Cinematographer

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    >>>Tom,
    Thanks for the info. I guess I just have a hard time getting the distortion figures of the Sunfire out of my head; small cube + PR = distortion in the midbass.> Actually, I was thinking more along the lines of the Velos. If you could source the right amp(and add just a bit of EQ, lose the servo), you could bring out a similar product at a considerable savings. No, the performance wouldn't be equivalent to the "waterheaters", but then again, I doubt that most folks would expect it to be. I'd think that the performance of the Velo HGSs would be a decent target, although I recognize that the legal issues could be problematic. Back to that mini-cylinder idea...> With all the new models being released by SVS, maybe the price of the older models will go down (wink, wink).
     
  12. Jack Gilvey

    Jack Gilvey Producer

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  13. Tom Vodhanel

    Tom Vodhanel Cinematographer

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    >>>I've been using marine ply, but I finally found a place that had that Baltic Birch in stock and it's *incredible* stuff. Expensive yes, but I don't see myself using MDF anytime soon. Impressive to see it used in such affordable subs. Of course, there are those who'll complain that you improve them at all.>>I don't think this is proprietary, and probably doesn't even belong in the hardware forum, but anyway it's a question I've had for a while:
    In simple terms,it's fairly easy to see how increased excursion/displacement will lead to more output above the tuning of a vented sub, the driver can move more air. What determines a driver's capabilites at and around Fb, though, where it's hardly moving at all and port output is at max? I'd assume that's where greater motor strength would come into play, allowing a driver to more effectively "work against" the damping action of the port for greater linear output. In that case, would "port compression" (assuming identical porting, not improved in any way) occur at the same output level for both a low-Bl and a high-Bl driver?
    Does any of this make sense? I've never really understood this relationship.
     

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